What aspect ratio is commonly used for Facebook instream video?

The commonly used aspect ratio for Facebook instream video is 16:9. This ratio is well-suited for horizontal video formats and aligns with standard widescreen video formats, making it visually appealing for users who engage with video content on various devices. Additionally, a 16:9 aspect ratio allows for a more immersive viewing experience, particularly on platforms like Facebook where users often watch videos in landscape mode on their devices.

Choosing 16:9 enhances the likelihood that the video will be displayed optimally across different placements within Facebook, ensuring that it captures the viewer's attention effectively. While other aspect ratios like 1:1, 4:5, and 1.91:1 may be used in specific contexts or for different types of content on Facebook, the 16:9 format is the most commonly recognized and utilized for instream video due to its versatility and broader compatibility with commonly used video production standards.